Incinerators for aqueous waste streams
Incineration is used to treat aqueous waste streams when biological processes are not a technically or economically viable option.

Incinerating waste streams comprising salt brines, aqueous liquids with organic contaminates, inorganic salts or metals pose many challenges. The most important consideration is that organic components have to be completely destroyed.

If inorganic metals (mainly alkalis) are present, designers must factor in the reactions in the gas phase as well as the reactions between the salts that have formed and the refractory linings.

Typical applications include:

Spent caustic from ethylene plants

Refinery waste

Pharmaceutical plant waste

Agricultural chemical plant waste

Bio-diesel plant waste

During the incineration process, most of the alkaline metals form salts with melting points lower than those required for the complete combustion of organics. These molten salts are corrosive to and reactive with common refractory materials. Selecting the correct operating temperature and lining material is crucial to ensuring that a plant maintains high availability.

Linde Engineering meets the application challenges of these complex wastes by down firing the incinerator into our proprietary Sub-X® vertical quench design to continuously remove salts from the incinerator walls. Our design is particularly efficient for this process as it rapidly cools the gases. The high level of agitation dissolves most of the salt into the quench liquor, thus ensuring that the gases undergo initial cleaning. Residual salts suspended within the gas stream at the quench outlet are scrubbed, meeting the most stringent air quality standards.